A process for producing substantially pure sucralose pentaester from a mixture of 6-O-acyl-4,1' ,6' -trichloro-4,1',6'-trideoxygalactosucrose in a reaction medium comprising a tertiary amide, wherein said process comprises the steps of:(a) recovering the 6-O-acyl-4,1' ,6' -trichloro-4,1' ,6' -trideoxygalactosucrose from said mixture;(b) peracylating the 6-O-acyl-4,1' ,6' -trichloro-4,1' ,6' -trideoxygalactosucrose product of step (a) to produce thereby 4,1',6' -trichloro-4,1' ,6' -trideoxygalactosucrose pentaester; and(c) crystallizing the 4,1',6' -trichloro-4,1' ,6' -trideoxygalactosucrose pentaester product of step (b) to produce substantially pure 4,1',6' -trichloro-4,1' ,6' -trideoxygalactosucrose pentaester.